key    partition   murmur2 & 0x7fffffff % 3 Math.abs(murmur2) % 3
o-1    0           0                        0
o-2    0           0                        2
o-3    1           1                        1
o-4    1           1                        1
o-5    2           2                        0
o-6    1           1                        1
